Nitrocellulose coating composition



Patented Dec. 11, 1934 I 1,984,061 NITROCELLULOSE COATING COIVIPOSITION Carleton Ellis, Montclair, N. J., assignor to Ellis- I Foster Company, a corporation of New Jersey No Drawing. Application June 19, 1926, Serial No. 117,151. Renewed May 6, 1932 4 Claims. (01. 134-79)" This invention relates to nitrocellulose coating under suitable conditions are converted to lower compositions, and particularly to such compoboiling so-called cracked or unsaturated derivsitions as can be applied to varioussurfaces by atives. Under the usual conditions a large 'means'of an ordinary paint brush. amount of liquid highly unsaturated derivatives 5 It is the object of my invention to produce suitable for use as motor fuel are obtained, t--

liquid coating compositions containing ,nitrogether with considerable amounts of gaseous uncellulose which can be brushed onto various sursaturated hydrocarbons, notably propylene, butyfaces with. a paint brush and which will dry lene and amylene. By adsorption in sulphuric quickly without leaving brush marks permanently acid with subsequent hydrolysis under such conon the surface of said coating. It is equally imditions as are now in commercial practice, these 10 portant that such compositions be of substangases are converted into isopropyl secondary butyl tially non-solvent action toward paint or varand amyl alcohols. The isopropyl alcohol can be nish films and of such nature thatthese compoconverted to acetone, the latter to diacetone alcositions can be brushed over such coatings with-= hol. Diacetone alcohol, secondary alcohols and out causing wrinkling or stripping of-said undercracked liquid hydrocarbons are thus obtained 15 coats. For household or interior use, it is adfrom petroleum under the conditions indicated vantageous to secure a product which contains and may then'be properly admixed and used acsolvents whose vapors are of non-toxic and noncording to this invention.

. cough inducing nature, preferably being of mild An example will serve to illustrate the invenand. not unpleasant odor. These qualities totion. Cellulose nitrate, usually called nitrocellu- 20 gether with low cost and durability of said coatlose, and preferaby of the so-called low viscosity ing composition are characteristic of my inventype is employed as the essential solid material tion. I of these compositions. In order to increase the It is further an object of my invention, at least thickness of the coating and produce more gloss in the preferred form, to employ as the nitroand better adhesion, it is desirable, although'not 25 cellulose vehicle solely certain petroleum derivnecessary, to incorporate a resin with the nitroatives of a volatile character. A vehicle of this cellulose. Various natural resins such as damar, nature iscomposite and illustratively contains dirosin and rosin ester, congo, kauri, shellac, and acetone alcohol as a dissolvent of nitrocellulose, the like, may be employed, although I prefer to petroleum hydrocarbons as an extending agent use a synthetic resin which is compatible with 30 or diluent and viscosity reducer, and a volatile nitrocellulose and of such nature as willincrease secondary alcohol as a homogenizer. Diacetone thedurability and which will confer greater film alcohol when admixed with petroleum hydrocarstrength than do the natural resins. 'A suitable bons of limited boiling point range, preferably synthetic resin may be made, f r x m l y such hydrocarbons as have been cracked and are slowly heating a mixture of 47 parts by weight 35 relatively highly unsaturated forms solvents of of glycerol, 80 parts of phthalic anhydride and 40 particular value. However,' the addition of parts byweig'ht of the distilled fatty acids from another liquid such as-a higher alcohol is necescottonseed oil, in a suitable container, to a temsary in order to properly blend the diacetone alperature of approximately 280 .C. An aluminum 40 cohol with the petroleum hydrocarbons and to "container closed at the .top with the exception 40 homogenize the nitrocellulose. The use of secof an air-cooled reflux condenser is suitable for ondary alcohols as the important homogenizing the purpose. Mechanical agitation is preferably agent has been found to be of particular value, employed continuously during the reaction and not only on account of their excellent homogenize the heating continued until a, sample has been iiig action, but also due to their non-cough inshown to possesssuiiicient hardness, or until the 45 ducing. and relatively agreeable odors, and to acid number has becomesubstantially less than their economic position such solvent mixtures as twenty. Resins may also be made the fatty have been found to be of particular value for the acids of other oils,- castor oil, rosin, and various production of nitrocellulose brushing lacquers carboxylic acids, although such resins are not 0 and which are'the feature of this invention can j exact equivalents of 'the cottonseed fatty acid be derived entirely from petroleum, thus insurproduct, since each will possess somewhat differing practically an unlimited supply and at such ent solubility, hardness and color. Polyhydric low cost as will permit of ready competition with alcohols other than glycerol may be used, likewise ordinary enamel or varnish products. to vary the hardness, color or solubility, as the High boiling-petroleum distillates when treated case may require. Glycol,,pentaerythr itol, manso "Other pigments,

nitol, and the like, are suitable polyhydric hols.

It is desirable to incorporate with the nitrocellulose, either when used alone or in combination with resins, a softener or plasticizer, such as castor oil, diethyl or dibutyl phthalates, tricresyl phosphate, mixtures thereof, or like materials. 1

Pigments'or dyes may beadded to produce enamels or stains of various colors, according to the object desired. A blue lacquer enamel su table for brush application was made as follows:

40. parts by weight of diacetonealcohol were admixed with 30 parts by weight of liquid cracked alco petroleum. hydrocarbons boiling between 70 and 130 C. 30 parts by weight of secondary butyl alcohol were then added. 12 parts by weight of one-half, second viscosity nitrocellulose with lzfparts by weight castor oil phthalic glyceride resin were then added to this balanced vehicle and the mixture agitated until complete solution was obtained.- The resin was made according to the proportions, and in' the same manner as previously described. :Pigment and plasticizermay be added to the clear lacquerand the whole well ground together in a ball mill or the pigment and 'plasticizer may be ground alone, or with the addition of some diacetone alcohol in a paint'mill or roller mill and then added to the lacquer composition. In the present example 4 parts by weight of Prussian blue and 8 parts by weight of zinc oxide were well ground in'a ball millwith 2 parts by weight of dibutyl phthalate, 2 parts byv weight of tricresyl phosphate and 4 parts by weight of blown castor oil .and said mixture ,then introducedand admixed with the clear lacquer to. form a blue lacquer enaniel suitable for brush application. Thefore- .going example is'given merely as an illustration than 20 P ent by weig of a particulanbrushing composition and is not to be construed as limiting, since many variations in. proportions 'of ingredients and the methods of manufacture may readily be made without departing from theprinciples of my invention. and plasticizers may be used,.or entirely omitted, when desired, accordingtothe object in view. High resin content tends to increase gloss, while high pigment con- 'tent decreases gloss. High viscosity nitrocellu- 'lose, may, in some cases,'be, used, although not as desirably. Many variations in the method of incorporating the various ingredients are possible, and are all considered within the scope of this invention. r

The feature of may invention of utilizing a peculiarly well balanced nitrocellulose vehicle, by means of which, in the preferred form, l obtainfat low cost a relatively non-toxic and noncough inducing composition, capable of being applied to paint, or varnish surfaces-without wrinklingorblisteringsaidsurf esandwhich on application will brush marks.

Qlhe essential feature isthat' of incorporating nitrocellulose with diacetone alcohoL- a liquid petroleum hydrocarbon of limited boiling point range and preferably of a cracked or unsaturated nature, by means of a solvent which acts as a homogenizing agent. point and preferably the'secondary alcohols such I Alcohols of proper dry substan ially free from ma a To a e of 8d by weight of diace= tone alcohol ended parts by weight of cracked petroleum drocarbons boiling between 8W C. and Mi? 0; d parts by weight of one=half second viscosity nitrocellulose and 8 parts by weight of a synthetic resin-made from glycerol phthalic anhydride and castor oiL'Were added. Afterex= tended agitation it was observed that a twolayer system had been formed, in which the ni= trocellulose in solvated form were contained in the lower layer and the resin in the upper layer- -The addition of 20 parts by weight of a secondary butylalcohol sufliced to bring about com-= plete homogenity of the mixture despite the fact Y that secondary butyl alcohol is generally re 'garded as a non-solvent for nitrocellulose, While compositions having some good properties may be derived from mixtures'of diacetone alcohol and secondary alcohols alone, such solvents have been found to produce solutions oi abnormally high viscosity and to often yield defective films on drying. The addition of cracked petroleum hydrocarbons has-been found to reduce the viscosity and to yield better films, so that the peculiar value of the tertiary solvent mixture isevidenced.

fWhile the proportions of the liquid components may be somewhat varied, it is usually necessary to have 'diacetone alcohol present in amount at leastequal to 40 per cent by weight of the total vehicle. Gasoline or petroleum hysdrocarbons boiling substantially betweenand 0., and preferably of a cracked and unsaturated nature are employed in amounts substantially' not exceeding 40 per cent by weight of the total vehicle and an alcoholic homogeniz ing agent such as isopropyl alcohol, secondary butyl alcohol or secondary mixed therewith in amount substantially not less employed.

It has been found very important to closely regulate the boiling point of the petrolelnn hy drocarbon fraction, taking care not to use hydrocarbons which boil substantially above the boiling point of the diacetone alcohol, particularly should no large amounts of such highboiling'material be used. Very tions, that is, approxima weight of the total solventw hydrocarbon boiling between ISO- C., has been added without causing serious trouble, but it is in most cases strongly advisable not to use a hydrocarbon boiling over 180 C. By using closely iractio 10 per cent by possible to regulate to a very large extent the brushing and drying ualities of these compositions, the brushing qualities tending to become poorer as the speed 0! drying is increased. The speed of dryingisdependent largely upon the boiling point, and more particularly upon the relative rates of evaporation of the vehicle.

In some cases ithas been found of advantage to use other acetone condensation products to partially displace a portion of the diaceton'e alcohol, e.g'., mesityl oxide. The addition 'of other substances such as butyl acetate, butyl propioamyl alcohol is adsmall proporcle of a petroleum nated hydrocarbon fractions, it is t of the total vehicle at nate, butyl butyrate; glycol ethers, glycol diacetate, ethyl lactate, butyl lactate, toluol, xylol, and other of the more common nitrocellulose solvents and diluents is not precluded, since I may utilize whereYfiiidesirable small amounts of these solvents in combination with my preferred vehicle.

embraces liquid coating composition containing nitrocellulose carried in a vehicle comprising a condensation product of acetone, preferably diacetone alcohol, "a petroleum hydrocarbon viscosity reducer and diluent, and'an alcohol homogenizer, said composition being capable of application to surfaces with a paint brush, without forming objectionable brush marks and without disintegrating undercoats.

What I claim is:--

1. A liquid coating composition containing low viscosity nitrocellulose carried in a vehicle comprising diacetone alcohol, a cracked petroleum viscosity reducer and diluent, and a secondary alcohol homogenizer.

2. A liquid coating composition containing low viscosity nitrocellulose carried in a vehicle comprising an acetone condensation product, an unsaturated cracked petroleum viscosity reducer and diluent; a resin, and a secondary alcohol .homogenizer.

4. A liquid coating composition containing niv trocellulose carried in a vehicle comprisingdiacetone alcohol, a cracked petroleum viscosity reducer and diluent, and an alcohol homogenizer; said composition being capable of application to surfaces with a paint brush, without forming objectionable brush marks, and without disintegrating undercoats.

CARLETON ELLIS. 

